Revert "Bug 1366312, remove oc set volume from 3.1 docs"
Revert "Bug 1366312, remove oc set volume from 3.1 docs"

This reverts commit e07b7cdcf092fd4f2ce308a0ab7b9dba79652f4c.

xiaoping378/openshift-docs,xiaoping378/openshift-docs,xiaoping378/openshift-docs